The New Science of Building

Creating a durable and efficient home is no job for amateurs.

There’s a common, but flawed, perception that older homes are more durable than newer housing, with fewer air, vapor and moisture problems. While it’s true that some newer homes may also have these problems, they were most likely designed and built by people who didn’t understand how to get the most out of cutting edge materials and construction practices. That takes an educated and experienced architect and builder.

In the not so distant past, someone with basic construction knowledge could design and build a serviceable home. No more. Today, the combination of state-of-the-art building materials and code-mandated construction practices have made homes more complex with less margin for error.

First, consider the evolution of materials. Suppliers used to sell framing lumber cut from mature trees that could absorb a lot of moisture without problems, a quality known as hygric buffer capacity. Builders put that lumber into walls that were not thoroughly sealed, where any moisture absorbed by the wood could escape before it caused problems.

But those mature trees have all been harvested. Today’s homes use a combination of engineered boards and dimensional lumber cut from fast-growing species—neither of which can store and release as much moisture as old-growth wood could. To complicate things further, energy codes mandate that those materials be put into well-insulated, tightly sealed airtight walls.

These are not drawbacks. Engineered wood offers real structural advantages, and well-insulated and airtight walls make homes more comfortable and efficient. The materials and insulation aren’t the problem; the problem is architects, engineers and builders who may be unfamiliar with how to specify, design and install these materials and systems. This is especially true in harsh mountain environments.

That makes it crucial to hire a design and building team who understands the basic principles of moisture-related and air infiltration building science. Yes, good design and construction is now a science as well as an art.

Knowledgeable architects and builders use stormproof roofing, siding, and flashing systems that keep water out of the structure, plus mechanical ventilation to keep air moving inside homes. They also know how to craft efficient water-managed wall systems that can handle moisture put into the home’s air by a typical family (from activities such as cooking and showering) without problems.

These architects, engineers and builders understand that air and vapor control is as important as moisture resistance, and that wall systems must be optimized for the local climate. The bottom line is to build the home so that its structure stays dry no matter how wet the weather or how well sealed the house is. A lot of older homes did that on their own, so builders and designers could get by without much knowledge of building science. That is no longer the case.